The objective of this research is to describe the neurophysiological characteristics of inputs to the simian oculomotor nuclei from the vestibular nuclei, the pontine and mesencephalic reticular formations and the cerebellum. Unit activity will be recorded in these structures while the animal is undergoing sinusoidal rotations about a vertical axis to excite the horizontal semicircular canals and simultaneously making voluntary eye movements in response to a moving target. In particular, preliminary results have shown that floccular Purkinje cells behave differently when the animal is fixating a stationary target rotating with him than when he undergoes compensatory vestibular-induced eye movements in tha dark. Therefore, the discharge patterns of units in the flocculus, vestibular nuclei and medial longitudinal fasiculus will be constrasted in the fixation vs compensation conditions. In addition, attempts will be made to demonstrate connections from mesencephalic burst neurons to oculomotor neurons by showing a buildup of the averaged synaptic potential in the motor nucleus when the average is triggered from single spikes in the burst.